1. Field of the Invention
The present invention relates to a bladder setting apparatus capable of automatically setting a bladder to, and removing it from, the center mechanism of a tire vulcanizing press, and to a carrying apparatus for automatically carrying the bladder to, and from, the center mechanism.
2. Description of the Related Art
First the tire vulcanizing press will be explained with reference to FIG. 8. The tire vulcanizing press has a lower mold 102 fixedly mounted on a lower mold mounting member 101, an upper mold 104 which is fixedly mounted on an upper mold mounting member 103 and can open and close towards the lower mold 102, a pressure cylinder 106 which applies a pressure to a pressure transmission rod 105 vertically provided on the upper mold mounting member 103, and a center mechanism 107 vertically movably disposed at the center of the lower mold mounting member 101. Either of the lower mold 102 and the upper mold 104 has a built-in heating means, and the center mechanism 107 has an inflatable bladder 111 for pressure and heat application under the supply of a heat pressure medium in contact with the inner surface of a green tire.
In the above-described tire vulcanizing press, the bladder 111 repeats expansion and deformation operations under a high-heat, high-pressure environment every curing cycle and therefore requires replacement with a new part at intervals of about 5 to 8 days. Also in the event of a flat tire or a tire having such a damage as a hole, the bladder 111 requires replacement at the time of mold change. As shown in FIG. 9 showing a conventional apparatus, the bladder 118 held at the top and bottom by a top ring 116 and a bottom ring 117 is replaced in one set by the use of a carrying apparatus comprising such a lifting equipment 115 as a fork lift truck. That is, a new bladder 118 laid outside of the press is lifted by the lifting equipment 115, and moved to a position just above the center mechanism 107, where the new bladder 118 is lowered. Subsequently, the bottom ring 117 is turned by hand to be screwed on the upper portion 120a of a hub 120 of the center mechanism 107 and then the top ring 116 is secured through a bracket 122 to the top end 121a of a center post 121 of the center mechanism 107, thereby setting the new bladder 118 to the center mechanism 107. An old bladder 118 is removed by reversing the above procedure.
The conventional setting apparatus, however, has such a problem that since the bladder 118 is manually installed to the center mechanism 107, technical man power and time are required. Also, the installation of the bottom ring to the hub 120, being done near the lower mold which is hot, is hazardous to the engineer, and therefore the adoption of an automatic locking device has been proposed. At present, however, the installation of the top ring 116 to the center post 121 is still performed manually. The carrying apparatus comprising the lifting equipment 115 such as a fork lift truck also has the problem that since the bladder 118 is brought by the fork lift truck to a position right above the center mechanism 107 and is then lowered, the centering of the bladder 118 can not easily be done. It, therefore, takes much time and labor for carrying and setting the bladder 118, and moreover a technical skill is required.